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relbeig 10-18-2009 09:49 AM

How to stop sump pump discharge pipe freezing???
When I bought this house I had no idea that it sits on a very high water table. My sump pump can run almost every ten minutes in the spring and fall even though my neighbours' rarely seem to discharge. I live in Ontario where it gets pretty cold and often my sump pump is discharging when it is very cold outside. The problems are: 1) my sump discharges at the front of my house and runs onto my grass and then freezes on the sidewalk - often gets to more than an inch thick; 2) my neighbour gets annoyed as most of the icing ends up on his driveway and sidewalk due to slope of street; 3) I have connected 1 1/2" pvc pipe to divert the water into my back yard and this works well except in the winter, when the pipe often freezes up.

My questions are: 1) I have thought of drilling a small hole in the pipe near the beginning of the discharge pipe to break the vacuum to allow the pipe to drain faster - will this be OK? 2) The discharge pipe is about 25 ft long and I have wondered if I could put roof deicing cable inside the pipe to prevent it from freezing - I would drop the end of the cable a couple of feet into the vertical sump pipe in the house wall to prevent the force of the water (hopefully) from pushing the cable out, and then simply run it inside the pvc pipe to the end. Do you think this might work? 3) Any suggestions that might work better??

I have read of others who suggested connecting to a 4" or 6" pipe, but there is an outside steel chimney on the same wall that prevents me getting more than a 1 1/2' pipe behind it. I guess I could try changing the discharge pipe to a larger size once it is beyond the chimney pipe??? I also wondered if it might be best to have the 1 1/2" pipe discharge into roof gutter after the chimney, and simply put roof deicing cable along that roof gutter until it emptied into my back yard??

This will be my 5th winter with this problem and I'm almost pulling my hair out. for the city to connect me to the street sewer, the cost will be over $11,000 which I can't afford. Please let me know if you have suggestions.

Daniel Holzman 10-18-2009 10:16 AM

I have a similar problem, although not as extreme since I live in the Boston area. You can reduce the freezing pipe problem by making sure that the outlet pipe has either continuous up pitch or continuous down pitch after it leaves the basement. If the pipe pitches down continuously, then water will drain out of the pipe by gravity, and there will be no water left in the pipe to freeze. This only works if the outlet is dry enough that you don't have standing water that freezes at the outlet.

If you have a pipe with continuous up pitch, the the water will want to drain back to the sump when the pump turns off. If you have a backflow preventer, the water cannot drain back into the sump, and will freeze in the pipe if it sits there long enought. Most people put a 1/4 inch down facing hole in the outlet pipe within the sump pit, which allows the water to drain back into the pit after it turns off. I found that my entire system works better with NO backflow preventer, and I don't need the 1/4 inch hole. Of course, this reduces the efficiency of the operation, because I am draining approximately 25 feet of line back into the sump pit for each pumping cycle, but my pipes do not freeze, and the removal of the backflow preventer increases the flow rate by eliminating some friction.

As for the heat tracing, you could insulate the pipe and heat trace the outside of the pipe to eliminate freeze potential. I am not familiar with any heat tracing products designed for use inside a pipe.

Scuba_Dave 10-18-2009 10:28 AM

Are you located at the bottom of a hill?
Is there any area where the ground drops off where you can direct water away from the house?
Is the ground around your house sloped away from your house?
I resloped the ground around my house & extended some down spouts 25' away underground that has virtually eliminated my sump pump from running

relbeig 10-18-2009 12:05 PM

Thanks, Daniel
I have a downslope on the pvc pipe, but I think that with the slight vacuum on draining, it empties quite slowly, allowing a certain amount of the water to be frozen on the bottom of the pipe. Over time this can get quite thick. I am going to drill the small hole near the beginning of the pipe to see if I can get it to drain quicker and maybe eliminate this problem.

do you think that wrapping heat tracing cable around the pipe might work? The ones I found all said not to be used for drain pipe - not sure why.

do you think it might help if I wrapped the pipe with insulation?

Thanks for the suggestions.

relbeig 10-18-2009 12:13 PM

Thanks, Scuba Dave
The only downslope around my house is to the front and left towards the sidewalk and my neighbour's driveway. There is a very slight downslope in the backyard away from the house so that is where I direct the water.

I have a deck along the back of the house, and a garage along the right side, so am not able to alter any slope there - although that doesn't seem to be a problem in either case. At the front there are large shrubs and cedars so I can't get at the front wall, and at the left there is a flower bed but it doesn't get a lot of rain due to the overhang of the roof - after the flower bed it does slope away - but towards my neighbour's driveway!

The houses around here are all about 200 yards away from a couple of large ponds and the ground is very heavy clay. I can't figure out why my house sump pump seems to run more than my closest neigbour's, unless there is an old stream running under my basement on it's way towards the ponds.

Thanks for all the suggestions.

AllanJ 10-19-2009 08:46 AM

deleted d.

ConcreteTreat 03-28-2011 12:32 PM

Hey there -- I know it's been a while since you've asked, but if you're still having issues, I suggest that you add a grated drain section at the opening of your discharge line. Then, if your discharge line DOES freeze, the system has a second "out" that doesn't include the inside of your basement.

Now, this is not to say I'm a fan of discharging water directly around your foundation, but if the ground is really frozen, then it won't be as big of an issue as it would be in other weather. The idea is in use by many successful waterproofing contractors, and it can be incorporated along with all these other ideas.

Anyways, just a thought you might like to try out.

Concrete Treat: Concrete Sealer
Revolutionize Your Construction!

melgil 11-12-2012 11:35 AM

This may not be relevant at all anymore, but I thought I would share that we had the same problem as you. We are also in Ontario so weather would likely be similar to you.

We have been in our home for 2 years and our sump pump was always going off about every 10 min. while the neighbours rarely, if ever went off. We can't direct to the rear of the house as the yeard slopes towards the house, but were running the discharge pipe down the side of the house which either saturated the neighbours yard or created a skating rink on the sidewalk in the winter.

We are in a marshy type area with some ponds and streams and as such have a higher water table than some other areas of town. Our neighbour has lived in the house for 20 years and reccomended moving the float i the sump pump up a bit, as he did that and hasn't had the sump pump go off in years.

We tried it, and it has been 1.5 years with no automatic discharge of the sump pump. It seems to sit about 1/4 to 1/3 of the way full and not move at asll.

We of course manually discharge the pump once a month to keep the system working and not to let the water get stagnant and it seems to work great for us. and no more water issues!

AllanJ 11-12-2012 12:03 PM

Your sump pump was fighting the normal level of the water table under not so wet conditions.

In that case, moving the pump turn on float a little higher can sometimes put the turn on level just above the water table and drastically cut down on pump operation. This is usually a trial and error process.

The water table can vary by several inches from one end of the house to the other. If you move the float level up too high, then you could get water up on the basement floor at the far end of the house even though the pit is not full.

Aside from this, there is no harm if there is a lot of water in the pit for long periods of time before the level gets high enough to turn on the pump.

The chances of the sump pump outlet pipe freezing are reduced if the pipe is continuously down sloping away from the house. That is, no hills and dales (bellies).

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